PC (personal computer) based graphics software systems are commercially available for professional photographers and other experts in digital imaging. They typically permit the user to increment (or decrement) individual variables such as brightness, contrast, or hue, and to see previews (thumbnails) of a single increment of change in two or more related variables before the selected change is applied to the underlying data. However, many variables can be manipulated on the same screen, the interrelationships between the various variables are not readily apparent, and many combinations of interrelated variables are not previewed. As a result, the novice user is overwhelmed with information and choices that have no apparent relationship to a desired change to the displayed image,
Particularly when attempting to edit a color image, a novice user without a basic understanding of color science does not know how to translate a desired improvement in an image into the specific values for the Red, Blue and Green (RBG), or Cyan, Magenta, Yellow and Black (CMYK) parameters corresponding to the input and output signal channels associated with color scanners, color monitors, color printers and other color-oriented electronic devices. Indeed, many users do not realize that Magenta is the opposite of Green, that Cyan is the opposite of Red, and that Yellow is the opposite of Blue.
A general purpose graphical user interface such as Microsoft Windows.TM. permits the programmer to designate certain portions of the screen as "buttons" which may be selected and operated by positioning and actuating a pointer device such as a "mouse". When the button is so actuated, the user receives an acknowledgment in the form of a visible change to the button's appearance, and the user interface invokes a software process designated by an "icon", text, or other graphics on or adjacent to the button.
However, the known user interface designs for graphics software applications do not provide an intuitive and unambiguous way for the novice user to make a reversible sequence of simple image adjustments such as more blue followed by less blue. As a result, many users of graphics software do not even try to change the color or other tonal characteristic of an image because they fear that they will make the image look worse instead of better.